Firearm with fortary magazine and pivoting rear barrel section



Aug. 29, 1961 w. E. ROSEBUSH 2,997,924

FIREARM WITH ROTARY MAGAZINE AND PIVOTING REAR BARREL SECTION Filed Aug.5, 1960 3 Sheets-Sheet 1 7 if A? gr INVENTOR .T/QOSEBUSH ATTORNEY 1961w. E. ROSEBUSH 2,997,924

FIREARM WITH ROTARY MAGAZINE AND PIVOTING REAR BARREL SECTION Filed Aug.5, 1960 3 Sheets-Sheet 2 02 7.2 4:1 93 /0/ l; 2a 33 /aa m6 L' I 4 /7x/1/ 11/777 Ill/I77 I l INVENTOR Wit/Po 555(15/4 ZKKW ATTORNEY Aug. 29,1961 w. E. ROSEBUSH FIREARM WITH ROTARY MAGAZINE AND PIVOTING REARBARREL SECTION Q 3 m? v Q mw m \x m\\ m m Nw s 3 \k m mm m. Q mu 3 mm 0AR km 3 a Q Q I M XW/ J .1 HQ .0 91 mi? NR- 9 1 n3 A NQRQ g L m m NM 1 mWITH ROTARY MAGAZINE AND PIVOT- ING REAR BARREL SECTION Waldo E.Rosebush, 41 1 Washington St., Appleton, Wis. Filed Aug. 5, 1960, Ser.No. 47,724 11 Claims. (Cl. 89-155) This invention relates to a novelconstruction of firearm having a rotary magazine provided with aplurality of chambers each adapted to contain a number of cartridges andwhereby the capacity of the magazine may be increased considerablywithout an appreciable increase in the over-all size of the piece.

Another object of the invention is to provide a firearm including ahingedly mounted barrel section which is movable to a position inalignment with a chamber of the magazine for receiving a cartridgetherefrom and thereafter to a position in alignment with the stationarybarrel section, for firing of the piece.

A further object of the invention is to provide a firearm wherein saidmovable barrel section is connected to and moves in unison with atrigger.

Still another object of the invention is to provide a firearm havingnovel means to automatically turn the rotary magazine, after eachchamber thereof is emptied, to align another chamber of the magazine,containing cartridges, with the hinged barrel section, when said barrelsection swings to a position for receiving a cartridge from themagazine.

Still a further object of the invention is to provide a firearm having anovel form of ejector operating through the firearm hammer for ejectingthe cartridge cases automatically from the bolt and bolt housing duringrearward recoil travel of the bolt.

Various other objects and advantages of the invention will hereinafterbecome more fully apparent from the following description of thedrawings, illustrating a presently preferred embodiment thereof, andwherein:

FIGURE 1 is a side elevational view showing the improved firearm in theform of an automatic pistol and looking toward the left side thereof;

FIGURE 2 is a top plan view of the pistol;

FIGURE 3 is an enlarged fragmentary longitudinal sectional view, partlyin side elevation, showing parts of the pistol in the positions assumedthereby, immediately after firing of the piece and during ejection ofthe empty cartridge case;

FIGURE 4 is a view similar to FIGURE 3, illustrating the position of theparts immediately prior to firing of the piece;

FIGURE 5 is an enlarged longitudinal sectional view, partly in sideelevation, showing certain of the parts of the pistol in the positionsassumed by the parts for feeding a cartridge from the magazine to thebarrel;

FIGURE 6 is a fragmentary side elevational view, partly broken away andpartly in section, illustrating the relationship of the parts,constituting the magazine actuator, to one another;

FIGURE 7 is an end elevational view looking toward the rear end of thebarrel and the hinged carrier thereof;

FIGURE 8 is an elevational view, partly in section, looking toward theforward end of the magazine and illustrating one position of the partsof the magazine actuator;

FIGURE 9 is a cross sectional view through the magazine and magazinehousing, taken substantially along a plane as indicated-by the line 9-9of FIGURE 5;

FIGURE 10 is an end elevational view, on areduced scale, of the magazineand magazine housing, looking from right to left of FIGURE 5;

i United States Patent 0 2,997,924 Patented Aug. ,29, 1961 FIGURE 11 isa front elevational view of the hammer, on a reduced scale, relative toFIGURES 3 to 5;

FIGURE 12 is a rear elevational view of the hammer;

FIGURE 13 is a side elevational View of the hammer and showing theejector extending therethrough, and

FIGURE 14 is a fragmentary view similar to FIGURE 8 and illustrating adifferent position of the magazine actuating parts.

Referring more specifically to the drawings, the firearm in its entiretyis designated generally 15 and is illustrated in the form of anautomatic pistol, preferably of small caliber; however, as thedescription proceeds it will be readily apparent that the invention isequally well adapted to other types of automatic firearms such asrifles. The pistol 15, as illustrated, is of .22 caliber.

The pistol 15 includes a frame, designated generally 16, having anelongated top and forward portion 17, constituting one end thereof, aguard strap v18, constituting the other end of said frame, and a triggerguard 19 extending between the frame portion 17 and the guard strap 18.

The forward and top frame portion 17 is recessed as seen at 20, saidrecess 20 opening upwardly therethrough and extending to adjacent afront face 21 of the portion 17 and through an arcuate concave rear end22 thereof. The forward end of the recess 20 is of reduced depth and hasan upwardly facing shoulder 23.

A forward and stationary barrel section 24 is provided adjacent itsforward muzzle end with a depending boss 25 which fits snugly in theforward end of the recess 20 and has a part of its lower end resting onthe upwardly facing shoulder 23. A pin 26 extends transversely through aforward part of the frame portion 17 and through an opening 27 of theboss 25 for detachably securing the barrel section 24 immovably to theframe portion 17. The barrel section 24 has an enlargement or collar 23at its rear end which is provided with depending transversely spacedaligned hinge barrel portions 29 which are located behind and spacedfrom the rear end 22 of the frame portion 17.

A carrier member, designated generally 30 and best seen in FIGURES 5, 6and 7, has a substantially straight top portion 31, the forward end ofwhich fits turnably between the hinge portions 29 and is pivotallyconnected thereto by a bushing 32 surrounding a pin 32', to form a hingeor knee joint between said end of the carrier 30 and the rear end of thestationary forward barrel section 24. A rear barrel section 33 ismounted on and fixed immovably to the upper or outer edge of the topcarrier portion 31 for swinging movement therewith and has a forward end34 which abuts flush against the rear end of the barrel section 24, in afully raised position of the carrier 30, as seen in FIGURES 3, 4 and 6,and in which position the bore 35 of the rear barrel section 33 alignsfully with the bore 36 of the forward barrel section 24, both of whichbores are rifled and with the riding of one constituting a continuationof the rifling of the other. The carrier 30 includes a rear portion 37,as best seen in FIGURE 6, which extends downwardly from the rear end ofthe barrel section 33 and which is curved so that its outer or rear face38 is disposed concentric with the hinge axis 32.

A trigger housing is composed of complementary side plates 39 which aresecured to opposite sides of the carrier 30 by pins 40. The side plates39 have back edges 41 which are disposed flush with the rear face 38 ofthe carrier portion 37, and said plates 39 have concavely arced forwardedges 42 between which a trigger 43 is secured by pins 44. The trigger43 is located beyond the lower free end of the rear carrier portion 37,as seen in FIGURE 6.

One end of a contractile coil spring 45 is anchored be- -other and fromthe axis of said magazine.

tween the side plates 39 by a pin 46, which extends therethrough, saidspring end being disposed above the trigger 43, as seen in FIGURE 4. Thespring 45 extends forwardly from the trigger housing 39 longitudinallythrough the recess 20 and is anchored at its opposite end to a stud 47,forming an integral part of the frame portion 17 and which extendsupwardly into the recess 20. A part of the boss 25 rests on the stud 47to prevent the forward end of the spring 45 from being disengaged overthe upper end of said stud, when the boss 25 is secured to the frame 16.

A sear 48 has an opening 48 to loosely receive a lug '37 which projectsfrom a part of the forward edge of the rear carrier portion 37, saidsear 48 being pivotally mounted at a point spaced from its ends on apivot pin 49 which engages through the sear and said lug 37'. The sear48 is disposed between the side plates 39, forwardly of the carrierportion 37, and has transversely spaced fingers 50 constituting theupper end thereof and which straddle and are swingably movable relativeto the carrier portion 31 and which are disposed for swinging movementin corresponding notches 51 of the side plates 39 and recesses 52 in theunderside of the barrel section 33.

The rear carrier portion 37 has a recess 53 extending from front to reartherethrough and which opens outwardly of its back face 38, as seen inFIGURE 7, in which a lever 54 is mounted for swinging movement on a pin55, which pivotally connects said lever to the carrier portion 37, forswinging movement of the lever through said rear face 38. A compressionspring 56 extending through a forward part of recess 53 engages betweenparts.

of the sear 48 and lever 54 for urging both the lever and sear to swingclockwise about their pivots, as seen in FIGURE 6, since the spring 56engages the lever 54 above its pivot 55 and the sear 48 below its pivot49.

The pistol 15 includes complementary side plates 57 and 58. The righthand side plate 58 carries the pins 26 and 32' which connect with theleft hand side plate 57. Screws 60 engage loosely through plate 57 andframe 16 and threadedly engage in the side plate 58. A back strap 61 issecured between rear edges of the side plates 57 and 58 by pins 62 andhas a rearwardly curved lower portion extending downwardly below thecoplanar bottom edges 63 of said plates 57 and 58. The back strap 61 isspaced from the guard strap 18 and the plates 57 and 58 havetransversely aligned corresponding notches 64 which open downwardlythrough their bottom edges 63, between said guard strap 18 and backstrap 61.

A hollow one piece grip 65 embraces the notched bottom rear portions ofthe plates 57 and 58 and has a forwardly opening groove 66 accommodatingthe guard strap -18 and a rearwardly opening groove 67 accommodating theback strap 61. The grip 65 has a recess 68, extending from top to bottomthereof, of circular cross section for detachablyreceiving a cylindricalmagazine housing 69, parts of which engage through the notches 64. Thegrip -65 is detachably secured in position by a wood screw 65' whichengages through the guard strap 18.

A magazine 70 fits rotatably in the housing 69 and is provided with fivechambers 71 which extend from endto-end thereof and which are equallyspaced from one an- As seen in FIGURE 8, the magazine housing 69 has afront wall 72 which is provided with a central opening 73 and an opening74 which extends radially inward from a part of its periphery and whichis spaced from the opening 73. The opening 74 is disposed to selectivelyalign with the chambers 71 as the magazine 70 is revolved in the housing69.

73 and from which a threaded stem 77 projects. The

stem 77 threadedly engages a centrally disposed socket 78 which opensoutwardly of the forward end of the maga- --zine 70, so that the ratchetwheel 75 rotates with the maga- 4 i zine and relative to the housing 69about the boss 76 as an axis; however, the magazine 70 has a relativelyclose fitting engagement in the housing 69, as seen in FIGURES 5 and 9.When the housing 69 containing the magazine 70 is mounted in the pistol15,'as seen in FIGURES 1 and 5, the housing front wall 72 is disposed inclose prox imity to the carrier face 37 with only slight clearancebetween said carrier face and the-ratchet wheel 75.

Each of .the chambers 71 contains a follower 79 and a follower spring 80for feeding cartridges 81 therefrom through the opening 74, when thechamber of said magazine is in alignment with said opening. Thecartridges 81 are .22 caliber short cartridges and each chamber v71 isadapted to contain three cartridges; however, the magazine 70 could beconstructed to hold a greater or lesser number of cartridges in each ofits chambers 71.

A hammer, designated generally 82, is mounted for swinging movement on apivot pin 83 between the side plates 57 and 58 and above and behind theupper portion of the magazine housing 69. The pin 83 is supported bysaid side plates 57 and 58, and engages through the ham mer 82 near thelower end of the hammer. Hammer 82 has a forwardly extending nose 84near its upper free end and an opening 85 which extends from front torear therethrough, below the nose 84. The hammer 82 has a forwardlyopening recess 86 extending from its bottom through a front portionlocated beneath and adjacent the forward end of the opening 85, and saidhammer has complementary toes 87 extending from its forward edge, onopposite sides of the recess 86, As best seen in FIG- URES 3 and 4, theouter faces of the upper and rear portions of the trigger side plates 39are recessed, as seen at 88, and the toes 87 straddle and slidablyengage said recessed portions so that the tips of the toes 87 contactthe sear fingers 50 which protrude outwardly from the planes of therecessed surfaces 88, as will hereinafterbe described. A spring actuatedguide 89 i pivotally mount ed for rocking movement in the hammer recess86 on a pivot pin 90 which engages through said guide 89 nearer thelower end than the upper end thereof. A light compression spring 91seats in a socket 92 of the hammer 82, which opens into the recess 86,and the spring 91 bears against the inner side of the guide 89 above itspivot 90.

A bolt 93 of arch shape cross section has an internally restrictedforward portion 94 which engages around the forward barrel section 24and which provides a rearwardly facing arch shaped shoulder 95 whichbears against a forward end of a recoil spring 96 which is mountedloosely on the barrel section 24 and which has a rear end abuttingagainst the collar 28. The bolt 93 has a rear end wall 97 which isprovided with a vertically elongated opening 98 and a downwardly openingnotch 99, which is disposed beneath and in alignment with the opening98. The bolt 93 has an externally thickened knurled top portion 100which extends forwardly from the rear wall 97 to a point spaced from theforward end of said bolt, and the rear end of said thickened top portionis provided with a vertically elongated ejector opening 101. A rearsight 102 is secured to and extends upwardly from the rear wall 97 andis detachably fastened to the bolt 93 by a screw 103. An extractor 104is formed integral with the base portion of the rear sight 102 andextends downwardly therefrom through the rear portion of the opening 101and across the upper part of the opening 98. When the rear barrelsection 33 is in alignment with the forward barrel section 24, as seenin FIGURE 4, the rear wall 97 of the bolt is disposed behind the rearend of the rear barrel section 33 and the lower portion of the extractor104 bears against the inclined rear surface 105 of the barrel section33, when the bolt 93 is in its forwardmost position of FIGURE 4. t

Referring to FIGURE 5, an arm 106 forming a spring stop is formedintegral with and extends forwardly from an upper part of the back strap61 and has an opening 107 extending from top to bottom therethrough. Anelongated latch member 108 has a rocking engagement in a forwardlyopening groove 109 of the back strap 61. The latch 108 has furcations110 at its upper end straddling the spring stop 106 and pivotallyconnected thereto by a pivot pin 111 located adjacent the forward end ofsaid spring stop and the forward ends of said furcations. The latchmember 108 includes a bridge 112 which spans the upper edges of theinner ends of the furcations 110 and which is disposed above and spacedfrom the inner portion of the spring stop 106. The latch 108 has a head113 at its lower free end which is disposed beyond the lower end of theback strap 61 and which is provided with an inwardly opening socket orrecess 114.

The hammer 82 has a downwardly and rearwardly opening socket 115 in itsrear side and above its pivot 83 in which the hemispherical head 116 ofthe pin 117 has a rocking engagement. Pin 117 forms a guide for a coiledcompression spring 118 which is mounted thereon and the upper end ofwhich bears against the fiat underside of the head 116. The lower end ofthe spring 118 bears against the upper side of the spring stop 106 and apart of the bottom convolution of said spring bears on the bridge 112for urging the latch 188 to rock inwardly and away from the back strap61 about its pivot 111. The guide pin 117 extends loosely through theopening 107 of the spring stop.

The magazine housing. 69 has a knurled enlargement 119 at its lower endand the magazine 70 has a knurled bottom portion 120 which protrudesfrom the lower end of the housing 69. The bottom end of the magazine 70is also provided with a kerf 121, as seen in FIGURE 10. A lug 122projects from the underside of the knurled portion 119 and is spacedslightly from the knurled peripheral portion 120, so that said lug willnot interfere with rotation of the magazine 70. The lug 122 conformablyseats in the recess 114 for latching the housing 69 im movably in thepistol 15 and with the opening 74 thereof in alignment with the bore 35,when the barrel section 33 is in its inclined position of FIGURE 5.Thus, the housing 69 can only be latched in the piston 15 in this onepredetermined position. The latch head 113 is manually engaged anddisplaced outwardly for applying the housing 69 and magazine '70 to thepistol or for removing them therefrom.

The coplanar bottom edges 123 of the bolt 93 slidably engage and ride onthe coplanar top edges 124 of the side plates 57 and 58. The bolt 93 isheld applied to the forward barrel section 24 by a bolt housing 125 ofarch shape cross sect-ion, as seen in FIGURES 1 and 2 and partially inFIGURE 3. The housing 125 has substantially parallel side walls 126which straddle the bolt 93 and upper portions of the side plates 57 and58. The side walls 126 have forwardly opening notches 127 in which theends of the pin 26 engage for connecting the forward end of the housing125 detachably to the frame 16. A single screw fastening 128 extendsthrough one of the side walls 126 and is threaded into the side plate 57or 58, disposed adjacent thereto, for detachably holding the housing 125immovable on the pistol, in cooperation with the pin 26. The housing 125has an opening 129 extending from near the forward end of its roundedtop portion 130 downwardly to adjacent the lower end of its verticallyrounded rear wall 131. The partof the opening 129 formed in the top wall130 slidably receives the externally enlarged portion 100 of the bolt93, the forward end of which engages the forward end of the opening 129to limit forward movement of the bolt under the biasing action of therecoil spring 96 and to thus nor mally maintain the bolt in its positionof FIGURE 4. The top portion 130 is provided with a front sight 132which is disposed forwardly of the opening 129.

An ejector 133 has a rear end pivotally mounted in a forwardly openingrecess 134 of the rear wall 131 on a pin 135, said recess being disposedbeneath the lower rear endof the opening 129. The ejector 133 extendsforwardly from its pivot 135' through the hammer opening 85. The ejector133 has a cam surface 136 on its underside for engaging the rear surfaceof the hammer 82 and thereafter the bottom surface of the opening sothat the ejector is swung upwardly as the hammer swings rearwardly. Theupper edge of the ejector 133 is provided with a forwardly facingshoulder 137 which is disposed forwardly of the cam surface 136 butspaced from the forward, free end of said ejector.

The bottom wall 131 of the bolt housing has a forwardly extending lip138, as seen in FIGURE 5, which engages rearwardly opening notches 139in the side plates 57 and 58 to additionally maintain the housing in anapplied position, and which lip 138 is disengaged from the notches 139as the housing 125 is displaced rearwardly, after removal of the screw128, for disengaging the notches 127 from the pin 26.

As best illustrated in FIGURES 6 and 7, the lever 54 is providedintermediate of its ends with a laterally offset upwardly extendingintegral pawl 140, the tip of which is outwardly offset from theadjacent portion of the outer surface of said lever, as seen in FIGURE6. The outer surface of the lever 54, above the pawl 140, is recessed asseen in FIGURE 7 to clear the lug of ratchet wheel 75 with which italigns.

FIGURE 1 shows the pistol 15 ready to be fired, assuming that themagazine 70 contains cartridges 81 in the chambers 71 thereof. Thespring 45 urges the strigger 43 and trigger housing 39 to swing to itsposition of FIGURE 1, which corresponds to the position of said parts inFIGURE 5, in which position the rear barrel section 33 is disposed inalignment with the opening 74. The follower 79 and spring 80 of thechamber 71, which is in alignment with the opening 74, will feed theforwardmost cartridge from said chamber 71 into the breech of the barrelsection 33, as seen in FIGURE 5. When the trigger 43 is thereafterpulled rearwardly, toward its position of FIGURES 3 and 4, the triggerhousing 39, carrier 30 and barrel section 33 will swing from theirpositions of FIGURE 5 to their positions of FIGURE 4, with the cartridge81 contained in the breech 35 being carried upwardly to its position ofFIGURE 4. The outer portion of each chamber 71 and the side wall of thehousing 69, in alignment with the opening 74, are recessed or notched asseen at 142 to permit passage of the flange 143 of the cartridge casetherethrough. As said cartridge travels upwardly with the barrel section33, the base thereof will engage and ride over the cam surface 144 ofthe guide 89 to fully seat said cartridge in the breech, the guide 89yieldably rocking about its pivot and against the action of its spring91 to permit the cartridge base 143 to pass in front of the cam surface144.

As the barrel section 33 commences to move upwardly between the hammertoes 87, the upper ends of the sear fingers engage under said hammertoes to rock the hammer 82 rearwardly about its pivot 83. As the barrelsection 33 reaches its fully raised position in alignment with thebarrel section 24- the hammer toes clear the upper ends of the searfinger 50 for releasing the hammer 82 from its fully cocked position ofFIGURE 4. As the hammer commences its forward swinging movement underthe action of the compressed hammer spring 118, the tips of, the toes 87ride down the rear edge of the sear fingers 50 to cause the sear to rockcounterclockwise about its pivot 49 for swinging the sear fingers 50forwardly. The hammer nose 84 is propelled through the opening 98 tostrike the base 143 of the cartridge 81 contained in the breech 35 fordetonating said cartridge to effect firing of the piece 15.

It will be noted that the extractor 104 engages in front of the topportion of the cartridge base 143 when the cartridge 81 is in itsbattery position of FIGURE 4. Accordingly, when the piece is fired thebolt 93 is driven rearwardly by the recoil from its position of FIGURE 4toward its position of FIGURE 3. As the rear Wall 97 of the bolt is in.engagement with the hammer. 82, the

hammer will be swung back from its forward position, approximately asshown in FIGURE 5, and as seen' in FIGURES l and 2, toward its positionof FIGURE 3. The empty case 145 will be withdrawn from the breech 35, bythe extractor 104 and as it moves rearwardly the bottom portion of itsbase 143 will strike the forwardly facing ejector shoulder 137, as saidejector is swung Upwardly, by rearward swinging movement of the hammer82, for ejecting the empty case 145 from the pistol 15 through the boltopening 101 and the housing opening 129.

During rearward movement of the hammer 82, caused by recoil of the bolt93, the hammer toes 87 will swing upwardly in the recesses 88 to engagethe rear edges of the fingers 50, which have been returned to theirnormal positions of FIGURES and 6 by the sear spring 56, to again causethe sear 48 to rock counterclockwise about its pivot 49 as the fingers50 are swung forwardly by the toes 87 to their positions of FIGURE 3.

The recoil spring 96, by engagement with the shoulder 95, willimmediately return the bolt 93 to its forward position of FIGURES l, 2and 4 after extraction and ejection of the empty cartridge case 145 hasbeen accomplished, and the trigger spring 45 will, immediatelythereafter, return the parts 30, 33 and 39 to their positions of FIGURES1 and 5 so that another cartridge 81 can be fed into the breech 35 inorder that firing of the piece, as previously described can be repeated.

As the parts 30, 33 and 39 swing upwardly from their positions of FIGURE5, if there is another cartridge 81 in the chamber 71 which is-inalignment with the opening 74, said cartridge will be advanced so thatthe nose thereof will protrude through the opening 74 for engaging thecam surface 141 of the lever 54 to hold said lever seated in the recess53 until the pawl 140 has cleared the lug 147 of the ratchet wheel 75,which is in the path of travel of said pawl, as seen in FIGURE 8.Thereafter, the sear spring 56 will swing the lever 54 outwardly to itsfull line position of FIGURE 6. However, as the parts again swingdownwardly, the exposed cartridge nose 148 will again swing the lever 54inwardly to its dotted line position so that the pawl 140 will not touchthe ratchet wheels 75.

As the parts swing upwardly, after the last cartridge 81 has been fedfrom a chamber 71 into the breech 35, there will be no cartridge nose toengage the cam surface 141. Accordingly, the lever 54 will swingoutwardly to its full line position of FIGURE 6 before the pawl 140reaches the ratchet Wheel 75 so that the pawl will engage the ratchetlug 147 for turning said lug, the ratchet wheel 75 and magazine 70one-fifth of a revolution relative to the housing 69, to move anotherchamber 71 con- .taining cartridges 81 into alignment with the opening74. The lug 147 is shown in FIGURE 14 engaged by the pawl 140 and afterit has completed a partof its one-fifth revolution and before beingdisengaged by said pawl.

The knurled ring 119 enables the housing 69 to be held immovable whilethe magazine 70 is rotated by gripping the knurled surface 120 forreloading the magazine 70 through opening 74, when the housing 69 andmagazine 70 are removed from the pistol 15. The kerf 121 can be engagedby a tool for holding the magazine while unscrewing the ratchet wheel75.

Various modifications and changes are contemplated and may be resortedto, without departing from the function or scope of the invention ashereinafter defined by the appended claims.

I claim as my invention:

1. In a semi-automatic firearm, a rotary magazine having a plurality ofchambers each adapted to contain cartridges, a spring pressed followerin each of said chambers for feeding the cartridges therefrom, a barrelhaving a stationary front section and a rear section, a carrierpivotally connectedto said front. section and secured to said rearsection for swinging movement of the rear section with the carrierbetween an aligned position of the barrel sections and a position inwhich the rear barrel section is in alignment with one chamber of themagazine for receiving a cartridge therefrom.

2. In a firearm as defined by claim 1, said barrel sections having boresdisposed in alignment with one another, when the barrel sections arealigned, said bores being rifled and the rifling of the bore of theforward barrel section constituting a continuation of the rifling of thebore of the rear barrel section.

3. In a semi-automatic firearm as defined by claim 2, a cylindricalhousing detachably mounted in a part of the firearm and in which saidmagazine is rotatably mounted, said housing having a front wall providedwith an opening disposed to selectively align with the magazine chambersand through which the cartridges are fed to said rear barrel section.

4. In a semi-automatic firearm as defined by claim 3, a ratchet wheelsecured to said magazine and rotatably mounted beyond said housing wall,a lever pivotally connected to and carried by said carrier and having apawl, spring means bearing against said lever for urging the lever andpawl to swing outwardly of the carrier for posi tioning the pawl toengage and turn the ratchet wheel and magazine as the carrier swings ina direction for moving the rear barrel section into alignment with thefront barrel section, and said lever having a cam surface engaged by thenose of a cartridge remaining in said magazine chamber to hold the pawlout of engagement with the ratchet wheel, to prevent turning of themagazine, when at least one cartridge remains in the chamber which is inalignment with said housing opening.

5. In a semi-automatic firearm as in claim 1, a trigger connected tosaid carrier for swingably moving the rear barrel section, with thecarrier, out of alignment with said magazine chamber and into alignmentwith said front barrel section, and a trigger spring for returning saidparts to their original positions with the rear barrel section inalignment with said magazinechamber.

6. In a semi-automatic firearm as defined by claim 5, a hammer, meanspivotally mounting said hammer behind said carrier for swinging movementof an upper portion of the hammer toward and away from the barrel, ahammer spring engaging the hammer and urging the upper portion thereofto swing toward the barrel, and a spring pressed sear supported by thecarrier for engaging a part of the hammer as the carrier is moved bymanipulation of the trigger for swinging the hammer away fi-om thebarrel and to a cocked position and for releasing the hammer, when thebarrel sections are disposed in alignment, to effect firing of the pieceby the hammer striking the cartridge contained in said barrel section.

7. In a semi-automatic firearm as defined by claim 6, a bolt slidablymounted on said front barrel section having a rear wall forming abreechblock and provided with an opening in which a part of the hammermoves for striking the cartridge, a recoil spring mounted on the frontbarrel section and engaging a part of the bolt to resist rearward recoilmovement of said bolt and to return the bolt to a forward position, saidbolt havingan ejector opening, an extractor carried by the bolt toengage and remove the empty cartridge case from the rear barrel sectionduring recoil of the bolt, and an ejector for ejecting the extractedcartridge case through said bolt opening.

8. In a semi-automatic firearm as defined by claim 7, a bolt housingdisposed over said bolt and in which said bolt is slidably movable,means pivotally connecting a rear end of said ejector to said bolthousing, and said hammer and ejector having coacting cam portions forswinging the ejector upwardly as the hammer is swung rearwardly byrearward recoil movement of the bolt for effecting the cartridge caseejection.

9. In a semi-automatic firearm as defined by claim 8,

said hammer having an opening through Which said ejector operates.

10. In a semi-automatic firearm as defined by claim 1, a cylindricalhousing detachably mounted in a part of the firearm and in which saidmagazine is rotatably mounted, said housing having a front wall providedwith an opening disposed to selectively align with the magazine chambersand through which the cartridges are fed to said rear barrel section,and a spring projected latch member detachably engaging a part of saidhousing for detachably latching the housing in the firearm with saidfront wall opening disposed to align with a bore of the No referencescited.

